Research on the feasibility of eddy current displacement sensor with temperature variation for non-ferromagnetic detection material

Abstract

For eddy current displacement sensor(ECDS), the output impedance of probe coil is affected by the fluctuation of temperature besides displacement. All kinds of ECDS are based on the analysis of the output impedance of probe coil. When different combinations of environmental temperature and measured displacement could result in the same output impedance, the ECDS would fail in its function to measure the displacement because under such conditions the effects caused by the change of displacement would be completely compensated by the effects resulted from fluctuating temperature. This paper discusses and proves the one-one mapping relations between the environmental parameters [d, T] and the output impedance [R, X] for non-ferromagnetic detection material. This one-one mapping relations could provide a theoretical basis for the feasibility of eddy current displacement sensor working with temperature variation when non-ferromagnetic material is detected.